1. Field of the Invention
The invention relates to an implement for conveying products in an agricultural environment and, more particularly, relates to an improved nurse inductor assembly for conveying feed seed and other particulate material to a planting mechanism for application in an agricultural environment.
2. Discussion of the Related Art
In recent years, product delivery systems have been employed in agricultural implements to deliver seed, fertilizer and herbicides to planters and tool bars. As the size of agricultural implements continues to grow, the versatility of such implements becomes more significant. Large air carts or air seeders have become increasingly popular for planting seeds, fertilizer and other product without strict regard for the exact placement of the product. Typically, these large air carts are used for dry land farming (e.g., cereal crops, etc.).
For certain crop planting applications that require row crop planting or seed singulation (e.g., corn, soybean, etc.), the air cart can be combined with a nurse inductor assembly adapted to feed seed or other product from a larger storage hopper into smaller reservoirs located at on-row singulators or receivers. The combined air cart and nurse inductor assembly enables a farmer to singulate planting of seeds on-row from one central hopper filling location. Thereby, the combined nurse inductor assembly and air cart allows a farmer to plant more acreage before having to stop to fill the central hopper again, resulting in quicker planting and less labor while maintaining the precision spacing available by on-row singulation.
FIG. 14 illustrates a nurse inductor assembly 20 known in the art. The known inductor assembly 20 includes an inductor chamber 25 positioned below a main feed hopper 26 of seed product 28. The inductor chamber 25 includes forward and rearward walls 30 and 35, respectively, and a bottom wall 40 that define an interior cavity 42 therebetween. The assembly 20 further includes an inlet tube 45 that extends through the forward wall 30. The inlet tube 45 is angled relative to the forward wall 30 in a downward direction toward the bottom wall 40. The assembly 20 further includes an outlet tube 50 that extends through the rearward wall 35. The outlet tube 50 is angled with respect to the rearward wall 35 in an upward direction from the bottom wall 40. The diameter of the inlet tube 45 is shown equal to the diameter of the outlet tube 50. The cross-sectional areas of the inlet and outlet tubes 45 and 50 are uniform throughout their lengths.
The interior cavity 42 is configured to receive a supply of seed product from the main feed hopper 26. A known pressurized or forced air system (not shown) provides a stream of forced air to an inlet end 55 of the inlet tube 45. The inlet tube 45 is configured to direct the stream of forced air in a direction toward the seed particulates so as to agitate and entrain the seed particulates into the air stream. The outlet tube 50 is configured to pass the stream of forced air and entrained seed particulates from the inductor assembly 20 to a seed distribution system. The seed distribution system generally includes one or more distribution lines 60 operable to route or direct the stream of air and entrained product toward one or more receivers or singulators. The receivers are configured to perform on-row planting of the seed product to an agricultural field. Each receiver generally includes one or more metering unit bins or mini-hoppers located on top of a respective seed metering unit and an injector configured to uniformly apply the seed into a furrow in the ground.
The nurse inductor assembly 20 induces seed product into the air stream when and where there is demand for the product at the receiver. The demand for product is controlled by the level of product in each respective receiver on the output end of the seed distribution line. In a known mariner, the flow of air in the combined stream of air and entrained seed product escapes out an air vent at the receiver. The remaining suspended seed product drops under gravity into one or more mini-hoppers or meter bins, and is then applied precisely into a furrow in the ground. The receiver is designed to allow air from the combined stream of air and entrained product to escape when the seed particle level is well below the air vent, but to limit the amount of air to escape as the seed particle level approaches the air vent. A filled receiver prevents the escape of air, thereby reducing the capacity of the air flow through the inductor assembly 20 to induce the seed product into the distribution line. If the nurse inductor assembly 20 includes a plurality of outlet tubes 50, the flow of air will to go to the distribution lines that have open receivers that exhibit less air flow resistance. As the seed product passes through the meter and is planted, the seed pile shrinks in the receiver or mini-hopper until the end of the distribution line is uncovered. At that point, the stream of air and seed product resumes through the distribution line, and the seed pile in the mini-hopper is replenished.
The certain known nurse inductor assembly described above has several drawbacks. For example, the velocity of the combined stream of air and seed product through the distribution line 60 slows as the stream encounters the increased resistance associated with traveling through the deposited seed product at the receiver. Seed product allowed to be induced into the distribution lines below the minimum carrying velocity causes blocking of the seed distribution lines 60. Any seed product that had been entrained into the slower flowing air stream drops out under the force of gravity. A certain quantity of this seed product will fall back into the interior cavity 42 of the inductor chamber 25. The remaining quantity of dropped seed product will deposit toward low points in the distribution lines, increasing plugging opportunities.
In another example, FIG. 14 shows the certain known inductor assembly 20 having the inlet tube 45 and the outlet tube 50 opposed to one another and of the same cross-sectional area. The distribution line 60 typically attaches over the outside surface of the outlet tube 50, and therefore a cross-sectional area of the distribution line is greater than a cross-sectional area of the outlet tube 50. This geometry of the known inductor assembly 20 further enhances inducement of seed product into the distribution lines 60 at or below the product's minimum carrying air velocity. The inducement of seed product below the minimum carrying velocity enhances plugging at or near the inductor and/or in the distribution lines 60. This problematic plugging can be intensified by other additional variables—e.g., hillsides, humidity, longer delivery lines on larger machines, system air loss, etc. Furthermore, this known inductor geometry causes seed product and particulates to be deposited in the distribution lines following shutting off the air pressure from the air pressure source. As the air pressure drops, known inductor assemblies continue to pick-up seed product and particulates until the air velocity drops below the minimum carrying velocity. As a result, seed product drops out of the air stream and settles down at low points in the distribution lines. Depending on the delivery rate and the air pressure shutoff speed, known inductor systems cause a significant amount of seed product to be deposited in the distribution lines, causing plugging and inhibiting planting operation. Therefore, it is critical for known systems to have flat distribution lines.
Furthermore, certain known nurse inductor assemblies do not provide for an efficient method to clean-out or purge deposits of seed product in the nurse distribution system. To clean-out certain known distribution systems, an operator must empty the meter bins and/or mini-hoppers first, then empty the main storage hopper, purge the distribution lines, and empty the mini-hoppers again. This clean-out process is cumbersome and very time-consuming. Furthermore, certain known nurse inductor assemblies do not provide a means for regulating the flow of seed product in the distribution lines other than by adjusting the speed of a blower fan. Variable speed adjustment of the fan is not equally efficient for a wide range of seed product types and variable sizes.
Therefore, a need has arisen to provide an improved nurse inductor assembly and an improved method of forced air conveying seed product that provide sufficient carrying velocity before the seed product enters a distribution line. The need has also arisen to provide an improved method of regulating an induction rate of seed product conveyed in a nurse distribution system. The need has also arisen to provide an improved method of cleaning-out or flushing seed product deposited in a distribution line of a nurse distribution system. The need has also arisen for an improved method of selectively directing the trajectory of air into the inductor assembly for entrainment of seed product into an air stream for conveyance in a distribution line of a nurse distribution system. The need therefore has arisen to provide a simple, reliable, durable, and efficient system for conveying product in an agricultural setting or environment.